The primary objective of Core B (Clinical Core) is to collect high quality clinical information and biologic specimens from subjects which will allow accurate phenotype-genotype associations necessary for the success of Projects 1-4. A key to the success of the core is a highly experienced investigator team with a proven track record in subject recruitment, phenotype determination, and collection of biologic specimens in asthma. Using these resources and expertise we will complete the following specific aims: Aim 1. Recruit subjects and obtain clinical data and biologic specimens for Project 1. Specifically, we will: 1) screen approximately 150 subjects to determine their asthma/atopy status; and 2) perform subsegmental bronchial challenge with lipopolysaccharide (LPS) and dust mite allergen, and obtain bronchial cells for gene expression analysis in 40 characterized on the basis of asthma and atopy phenotypes (10 subjects with atopic asthma, 10 subjects with atopy but not asthma, 10 non-atopic asthmatics, and 10 non-atopic, non-asthmatics). Aim 2. Establish and characterize an African-American asthma cohort for genetic analysis studies in Project 2. We will identify and characterize the phenotype of 200 probands with childhood asthma, 2-3 first-degree relatives of each proband, and 200 age- and sex-matched non-asthmatic controls (total n=900). Aim 3. Perform allergen skin testing on subjects enrolled in Project 3. 250 subjects tmdergoing inhaled ozone challenge will be skin tested with a panel of allergens to establish their atopy status. Aim 4. Obtain human bronchoalveolar lavage cells and fluid for Project 4. Bronchoalveolar lavage cells and fluid will be obtained from 40 subjects undergoing research bronchoscopy in Project 1. A portion of BAL cells and fluid, and phenotype data will be transferred for use in Project 4.